The invention relates to a method of and apparatus for forming a food, particularly to a method of and apparatus for forming a food by surely wrapping an inner material such as bean jam, cooked meat and vegetables and the like with an outer skin material such as bread dough, bun dough and the like without damaging the dough.
As a technique for the formation of a food by wrapping an inner material with an outer skin material, it has been carried out conventionally that the cylindrical outer skin materials provided outside the inner materials formed in a rod shape are continuously formed in a food, which are narrowed by an open/close operation of a shutter mechanism, then the food is cut (e. g. Japanese Utility Model Publication No. 63/29433). However, when dough such as bread dough and the like having fermentation property is used as an outer skin material and formed in a cylindrical shape, a pressure or twist is applied to the outer skin material so as to damage the dough. After the dough is cut and formed in a food, the dough is not sufficiently swelled up, thereby rendering the food hard and non-elastic in the outer skin material, and hence the forming process is manually carried out at present. There is proposed a method of forming a food using a sheet-shaped outer skin material to avoid the cylindrical formation of the outer skin material. For example, Japanese Utility Model Publication No. 7-18299 discloses that bread dough and bean jam are filled in a cup and the bread dough is sealed by a sealing gate. Further, Japanese Patent Laid-Open Publication No. 2000-50854 discloses that an outer skin material is formed in a bowl shape along an inner wall surface of a cup-shaped female mold which is opened at the upper surface, and an inner material is supplied to the inside of the outer skin material which was formed in a bowl shape, then an upper peripheral portion of the outer skin material is narrowed by a shutter comprised of plural shutter members, thereby sealing the upper peripheral portion of the outer skin material with which the inner material is wrapped. When the outer skin material is narrowed and sealed by the shutter members, a plug is disposed in an opening of the female mold, thereby preventing the narrowed outer skin material from protruding toward the upper portion of the shutter members.
In the case of forming a food using a sheet-shaped outer skin material as set forth above, it is necessary to consider that the sizes of the outer skin materials are differentiated depending on the sizes of foods to be formed or the shapes of the outer skin materials are varied even if they have the same size. This is caused by the fact that although the outer skin material is frequently rolled by a pair of rotary rollers so as to form the outer skin material in a sheet-shape, it is difficult to render the shapes of the outer skin materials constant because dough has flexibility. However, the conventional food forming method using the above mentioned sheet-shaped outer skin material cannot sufficiently cope with the change of the shapes of the outer skin materials. For example, according to Japanese Utility Model Publication No. 7-18299, since the cup is used, an opening area of the cup is determined beforehand, and hence when both the outer skin material and inner material become large in the case of forming a large food, there is a likelihood that the outer skin material extrudes from the upper surface of the sealing gate when the outer skin material is sealed by the sealing gate. Although there was described the provision of a dough support height adjusting mechanism to cope with a large or small capacity of a product, which is however limited to the adjustment inside the cup, and hence the sufficient adjustment is not always assured. It is considered that a large cup is replaced by the cup depending on the size of a food, but it is not practical to change the cup every time when manufacturing various kinds of foods in a mass production process. Further, in the case of sealing the dough piece by the sealing gate which is placed on the peripheral portion of the cup, if the shapes of the dough pieces are varied, it is not avoidable that the surplus dough piece is extruded from the upper portion of the sealing gate and separated from the dough piece and remains as refuse. This is caused by the fact that since the size of the opening of the cup is determined, if the shapes of the dough pieces are varied, the width of the peripheral portion of the dough piece which is held by the opened edge of the cup is not uniform, so that the peripheral portion of the dough piece having the large width extrudes from the upper portion of the sealing gate when it is sealed by the sealing gate. The extruded dough piece is separated by the sealing gate and it remains on the upper surface of the sealing gate or dropped from the sealing gate and left inside the apparatus as refuse. If the remaining refuse of the dough piece is not removed, it enters a food to render the food defective, or it enters the apparatus to cause a trouble. It is conceived to uniform the shapes of the dough piece in advance to cope with such problems, which however results in addition of a process line, which causes the problem of taking much manufacturing time and increasing damage to be applied to the dough. Japanese Patent Laid-Open Publication No. 2000-50854 also uses a cup-shaped female mold, which has however a limit to cope with the sizes of the outer skin material and inner material because the food is formed using the cup as set forth above. Although the outer skin material is prevented from being protruded by the plug so as avoid the extrusion of the dough, a gap has to be provided between the shutter and the plug for operating the shutter because the plug is set in position by the vertical movement thereof. Accordingly, it is not avoidable that the dough clamped between the shutter members is pushed toward the gap between the shutter and the plug and extruded when the shutter is closed. As mentioned above, if the food is formed using the cup and the like, the formation is limited by the cup and the like, and hence such a method cannot flexibly cope with the dough pieces which are not constant in sizes, shapes and properties.
The invention has been developed in view of the problems of the conventional food forming apparatus, and it is an object of the invention to provide a food forming method and a food forming apparatus capable of simply coping with the sizes, shapes, and properties of outer skin materials and inner materials to be formed in foods, and capable of surely wrapping the inner material with the outer skin material while reducing damage to be applied to the outer skin material.
The food forming method of the invention comprises a disposition step for disposing an inner material on an outer skin material, a shutter step for operating a first shutter and a second shutter provided under the first shutter so as to wrap the inner material with the outer skin material. The food forming apparatus of the invention comprises a first shutter comprised of a plurality of shutter members, a second shutter disposed under the first shutter and comprised of a plurality of shutter members, and shutter control means for operating the first and second shutters respectively so as to wrap an inner material with an outer skin material.
Since the invention has a structure set forth above, a food is formed wherein the inner material can be surely wrapped with the outer skin material, thereby preventing the occurrence of refuse caused by the separation of the outer skin material. That is, when the opening areas of the first and second shutters are set appropriately corresponding to the sizes, shapes and properties of the outer skin materials and the inner materials and the first and second shutters are operated, the inner material can be surely wrapped with the outer skin material. Further, since the first shutter and the second shutter are operated respectively, both the first and second shutters are coordinated with each other in response to the sizes, shapes and properties of the outer skin materials and the inner materials and cope with them so that the peripheral portion of the outer skin material can be surely collected and sealed. Accordingly, it is possible to prevent the occurrence of refuse caused by the separation of the outer skin material.
In the shutter step, it is preferable that the operation of the second shutter is started after the operation of the first shutter was started. Further, it is preferable that the shutter control means comprises first shutter control means for operating the first shutter in a state where the inner material is disposed on the outer skin material, and second shutter control means for controlling operation start timing of the second shutter and also operating the second shutter so as to seal a peripheral portion of the outer skin material after an operation of the first shutter is started. In such a manner, if the first shutter is operated earlier than the second shutter disposed under the first shutter, a series of operations extending from the collecting operation to the sealing operation of the outer skin material can be effected smoothly.
Further, during the shutter step, it is allowed that the first shutter collects a peripheral portion of the outer skin material when it effects a close operation so as to wrap the inner material with the outer skin material, and the second shutter seals the collected peripheral portion of the outer skin material when it effects a close operation. By doing so, the sealing operation is effected by the second shutter after the peripheral portion of the outer skin material was collected by the first shutter, so that the inner material can be surely wrapped with the outer skin material. And the first shutter is rendered in a close state when the second shutter effects the sealing operation, thereby preventing the outer skin material from extruding.
During the shutter step, it is allowed that the first shutter operates to collects the peripheral portion of the outer skin material at an area surrounded by a plurality of shutter members of the first shutter, and the second shutter operates to seal the collected peripheral portion of the outer skin material. By doing so, the sealing operation is effected by the second shutter after the peripheral portion of the outer skin material was collected by the first shutter, so that the inner material can be surely wrapped with the outer skin material, and also the outer skin material is separated and no refuse is occurred because the first shutter and the second shutter are not rendered in a completely close state.
During the disposition step, it is preferable that the outer skin material is formed in a bowl shape. By doing so, the operation extending from the collecting operation of the peripheral portion of the outer skin material to the sealing operation during the shutter step can be smoothly effected. It is allowed that the formation of the outer skin material in a bowl shape is made by supplying the outer skin material onto the shutter members of the second shutter to recess a central portion of the outer skin material in a state where the first shutter is opened or supplying the outer skin material onto the shutter members of the first shutter to recess a central portion of the outer skin material.
When the outer skin material is supplied onto the shutter members of the second shutter and the central portion of the outer skin material is recessed so as to be formed in a bowl shape in a state where the first shutter is opened, it is preferable that the peripheral portion of the outer skin material is held on the shutters of the second shutter. By doing so, the outer skin material can be surely formed in a bowl shape. Further, it is allowed that the outer skin material is supplied to a receiving member disposed over the shutter members of the second shutter so that the peripheral portion of the outer skin material is held on the receiving member. When the peripheral portion of the outer skin material is held, it is allowed to be partially held. Further, it is allowed that holding means is provided with protuberances for partially holding the peripheral portion of the outer skin material. By doing so, the thickness of the outer skin material which was sealed by the shutters can be thinned.
In the case of forming the outer skin material in a bowl shape, it is allowed that the shutter members of the second shutter is opened and outer skin material forming means is advanced into an opening of the second shutter to recess the central portion of the outer skin material or the central portion of the outer skin material is drawn by the crust forming means through the opening of the second shutter to recess the central portion of the outer skin material. It is allowed that the curst material forming means is provided with pushing means for pushing the outer skin material into an opening area of the second shutter or provided with suction means for drawing the outer skin material through the opening area of the second shutter. It is allowed that the pushing means is provided with inner material supply means for supplying the inner material. By doing so, the forming process can be effected efficiently.
In such a manner, if the outer skin material is formed in a bowl shape using the shutter members, the shutter step can be effected immediately after the outer skin material was formed in the bowl shape, and it is not necessary to provide a space separately for forming the outer skin material in the bowl shape.
Still further, it is preferable that the first shutter is operated before the outer skin material is formed in a bowl shape to adjust a position of the outer skin material. By doing so, the positional displacement of the outer skin material after the supply of the outer skin material is adjusted in advance, so that the forming process can be more surely effected.
More still further, it is preferable to provide support means disposed under the second shutter for supporting the outer skin material and the support means supports the outer skin material at least during the shutter step. By doing so, the outer skin material can be kept in a stable state during the shutter step. Yet, it is allowed that the support means comprises a support member disposed under the second shutter for supporting the outer skin material and support interval adjusting means for adjusting an interval between the second shutter and the support member. If the interval between the second shutter and the support member is adjusted appropriately to form the food, it can cope with the sizes and the properties of the outer skin materials and inner materials to meet the situation.
Still further, it is preferable to provide plural pairs of the first shutter and the second shutter which are paired with each other. By doing so, the forming process can be effected at the same time, thereby enhancing the productivity.